From a chaotic group of hyperkinetic manifestations Friedreich separated an entity which was characterized by rapid, lightning-like twitchings of the muscles, or myoclonia. This syndrome, now known as Friedreich's paramyoclonus multiplex, he ascribed to abnormal irritability of the cells of the anterior horn. In 1891 Unverricht1 demarcated still another nosologic entity of myoclonic phenomena associated with epilepsy. He described several cases from the previous literature and added observations on a family composed of 5 sisters. These patients were afflicted between the ages of 6 and 13 years, first with generalized convulsions, followed in a few years by the onset of myoclonia consisting of irregular, arrhythmic lightning-like jerks of muscle groups without movements of the extremities. These affected both upper extremities first and involved the face last. Sleep abolished the movements; external disturbances, psychic upsets and volitional muscular effort increased them. Unverricht, too, expressed the belief that the myoclonia is
GRINKER RR, SEROTA H, STEIN SI. MYOCLONIC EPILEPSY. Arch NeurPsych. 1938;40(5):968–980. doi:10.1001/archneurpsyc.1938.02270110122008
Customize your JAMA Network experience by selecting one or more topics from the list below.